The present invention relates to carriage-mounted saw assemblies and, more particularly, to a concrete-cutting saw having a handle-actuated guide mechanism.
It is often desirable to cut openings in walls, including those made of concrete, stone, and other hard materials. Such cuts are best made using a saw mounted to a carriage for movement along a track attached to the wall. The carriage is typically guided along the track by a plurality of rollers or other guide elements bearing against contact surfaces on opposite sides of the track. Saws of this type are disclosed in U.S. Pat. Nos. 3,722,497; 3,763,8.45; 4,986,252; and, 5,078,119. Also of this type are a Meco WS-25 wall saw manufactured by Masterpiece Engineering Company of Orange County, California; a HWS-112 wall saw of Diamond Tech Incorporated, Roseville, Calif.; a DSM 700S wall saw of Gearmec Sweden AB; and a Wandsage-System Type RZ wall saw of Hydrostress AG. In each of these structures, the elements that guide the saw carriage also serve to retain the carriage in position on the track.
In the foregoing devices, a carriage can be mounted to or released from a track by retracting rollers holding the carriage in place. The rollers can be moved individually or the carriage itself can be split apart to move the rollers on one side of the track away from those on the other side. The process of disengaging the rollers thus requires significant attention on the part of an operator and undesirably complicates the mounting/dismounting procedure. The operator must remove one hand from the saw's carrying handles to move the rollers or split the carriage. During the maneuver, the saw must be held in position on the track, usually by leaning against it or supporting it with a leg or a shoulder. This can be extremely awkward and difficult to accomplish, due to the weight of the saw, its position on the wall, and peculiarities of the worksite. For example, wall saws are often mounted and operated from atop stepladders, scaffolds and swing stages, each of which can present a highly unstable work platform.
Another problem inherent in some prior wall saws is that the rollers do not retract sufficiently to permit the carriage to be moved directly toward or away from the track in a direction perpendicular to the wall being cut. It is then necessary to move the carriage laterally over the cut line to mount it or dismount it. This greatly complicates the mounting and dismounting procedures, especially when the saw is used to cut a line flush with an adjoining wall or other obstruction.
It is therefore desirable in many applications to provide a track-mounted saw which is simple and easy to use, and which can be mounted to or dismounted from its track without releasing a hand from the saw itself.